ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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allowed to dry in the air, and then fixed by passing twice through the 
flame. The next step is to decolorise in 1 per cent, sulphuric acid for 
1-2 seconds. The films are now washed in water, after which they are 
contrast-stained in very dilute alcoholic solution of methylen-blue for 
3-4 minutes. The preparations are then washed in water, dried, and 
mounted in balsam. 
Staining Bacterial Spores.* — Dr. G. Catterina gives the following 
method for staining the spores of B. antliracis , &c. The spores are 
spread on cover-glasses, and fixed in the flame or in nitric acid fumes for 
10-15 minutes. The preparations are then carefully washed with water, 
after which they are stained with Roux’s fluid (methyl-green 1, 70 per 
cent, alcohol 10, water 90), heated to boiling. The addition of some 
more methyl-green imparts a better staining. The preparations are 
washed in water, and then stained with cold phenol-fuchsin solution. 
After this they are washed in water, 50 per cent, alcohol, and water 
again. The preparations are inspected in water. 
Staining Bacteria in Tissues.f — Dr. C. Money states that the re- 
sults from treating sections in the following manner are extremely good. 
The sections are first stained in picro-borax- or alum-carmine, and then 
in gentian-violet or methylen-blue to which 2-3 drops of formalin to 
a watchglassful of the solution have been added. The staining solution 
is then heated until it begins to vaporise. The excess of stain is washed 
off with water, and the preparations decolorised in 90 per cent, alcohol. 
It is advisable not to leave the preparations too long in formalin-gen- 
tian solution, because the decoloration becomes tedious. 
Staining Plague Bacillus.^ — Dr. G. Boccardi gives the following as 
a good double stain for the plague bacillus in blood and pus prepara- 
tions. Stain for 10 minutes in alcoholic or aqueous solution of eosin ; 
wash in water, stain for one minute in weak methylen-blue solution 
(1-1000 water). 
Staining the Granules in White Corpuscles. § — Dr. G. Boccardi 
stains the granules in white corpuscles as follows. Fix the film for 
5 minutes in osmic acid vapour. Immerse for a few seconds in peroxide 
of hydrogen diluted with five times the amount of water. Wash in 
water. Stain for 10-15 minutes in 1 per cent, aqueous solution of 
eosin, then for half a minute to a minute in methylen-blue solution. 
By this procedure the small neutrophile granules are stained red.. 
Method of Staining Mucous and other similar Cells. || — The tis- 
sues, stomach, intestine, &c., says Dr. E. W. Carlier, should be fixed in 
sublimate or picro-sublimate, and after-hardened in alcohols of increasing 
strength. The sections should be washed in iodo-potassic iodide, and 
afterwards in water. The sections are stained on the slide in 0 • 5 per 
cent, aqueous solution of methylen-blue, patent B, for 10 minutes. The 
surplus stain having been washed off, the sections are treated with 0 • 6 
* Atti Soc. Veneto-Trentina, iii. (1898) p. 435. 
f Centralbl. Bakt. u. Par., l te Abt., xxv. (1899) p. 424. 
% Biforma Med., 1897, No. 168. See Centralbl. Bakt. u. Par,, l t0 Abt., xxv 
(1899) p. 237. § Tom. cit., p. 237. 
|| Proc. Scot. Micr. Soc., ii. (1897-8) p. 212. 
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